Because liquid crystal displays have a characteristic of color-shift phenomenon that comes along with the increase in view angle, and therefore reducing the color-shift problem has become one of the chief targets to achieve high quality liquid crystal displays. Referring to FIG. 1, FIG. 1 discloses a scheme view of a pixel displaying structure of a conventional liquid crystal display, wherein the liquid crystal display has a plurality of sub-pixel units 90, and the sub-pixel units 90 are arranged in a two-dimensional matrix arrangement, and at least one sub-pixel units 90 constructs a pixel unit. Each of the sub-pixel units 90 is divided along a horizontal line into a rectangular bright-partition 90A and a rectangular dark-partition 90B, wherein the bright-partition 90A is not necessarily equal to the dark-partition in size, and the bright-partitions 90A of the sub-pixel unit 90 arranged at the same row are corresponding to each other in position, and similarly the dark-partitions 90B are corresponding to each other in position. The division is achieved by varying alignment direction of liquid crystal molecules under the bright-partition 90A and the dark-partition 90B to make light flux of the bright-partition 90A to be more than the light flux of the dark-partition 90B. In any view angle of the liquid crystal display, the brightness of mixture of lights from the bright-partitions 90A and the dark-partitions 90B will be basically the same as the brightness we feel when we look straight at the liquid crystal display, so as to solve the color-shift problem.
However, with reference to FIG. 2, FIG. 2 is a scheme view of the next frame of the pixel displaying structure of the conventional liquid crystal display in FIG. 1, wherein the bright-partition 90A of the preceding frame turns into a dark-partition 90A′, and the dark-partition 90B of the preceding frame turns into a bright-partition 90B′, in other words, brightness and darkness change over between the rows of sub-pixel units on two consecutive frames of screen image. Foregoing means of changing over brightness and darkness between the rows of sub-pixel units will inevitably affect image quality during displaying an oblique line on screen due to the boundary between the bright-partition 90A and the dark-partition 90B of the sub-pixel unit 90, wherein a user will see a ladder-like (or zigzag) bright-dark boundary line 900 appearing on the oblique line constructed by a plurality of the sub-pixel units 90.
Hence, it is necessary to provide a liquid crystal display and a pixel displaying structure thereof to overcome the problems existing in the conventional technology.